Flutter + Kotlin (Flutlin)

Aim

To find out the way to utilize flutter UI design benefits while on logical tasks like rest api calling with Kotlin.

• UI design in Flutter
• Rest api calling with Retrofit in Kotlin.

Tech

• FlutterView (https://docs.flutter.io/javadoc/io/flutter/view/FlutterView.html)
• FlutterActivity (https://docs.flutter.io/javadoc/io/flutter/app/FlutterActivity.html)

Steps to follow to use Flutter View

1) Create Flutter Project.
2) Open android project in Android Studio.

* Create your own layout for your activity and add simple `FlutterView` 
    ```
    <io.flutter.view.FlutterView
            android:id="@+id/flutter_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent" ></io.flutter.view.FlutterView> 
* Need some initialisation for flutter as per below:
    ``` 
    val args = getArgsFromIntent(intent)
    FlutterMain.ensureInitializationComplete(applicationContext, args)
* Create `FlutterRunArguments`, provide context and entry point of dart for that view.
    ```
    val runArguments = FlutterRunArguments()
    runArguments.bundlePath = FlutterMain.findAppBundlePath(applicationContext)
    runArguments.entrypoint = "main"
* Bind your `FlutterView`
    ```
    flutterView = findViewById(R.id.flutter_view)
    flutterView!!.runFromBundle(runArguments)
* User any channel to communicate with your dart file and activity. In our case, I have used `BasicMessageChannel` to pass string as response.
    ```
    messageChannel = BasicMessageChannel(flutterView, CHANNEL, StringCodec.INSTANCE)
    messageChannel?.send(message)
* Close android project.

3) Open Flutter Project.

* Initialise `BasicMessageChannel` channel which will be helpful to fetch data shared in our Actitivy.
    ```
    static const BasicMessageChannel<String> platform =
    BasicMessageChannel<String>(_channel, StringCodec());
* Register callback in your `initState()` widget
    ```
    platform.setMessageHandler(_handlePlatformMessage);
* Create method as per below through which you can parse your string into response model and that you can use to reflect in UI.
    ```
    Future<String> _handlePlatformMessage(String message) async {
        // use setState() to reflect the message in  your ui.
    }

LICENSE!

Flutlin is MIT-licensed.

Let us know!

We’d be really happy if you send us links to your projects where you use our component. Just send an email to sales@mindinventory.com And do let us know if you have any questions or suggestion regarding our work.